Initially Google say that HTTPS will only be a mild ranking factor so Webmasters have a chance to make the necessary adjustments to their websites. Google warn that the weighting could change in the future.

This is going to have a massive impact on websites across the world. HTTPS is slower than normal HTTP and even banks keep the majority of their content “in the clear”.

HTTPS is slower than HTTP because:

The server and the browser have to make additional handshaking exchanges

Each page has to be scrambled up in a unique way for each visitor

Each page has to be descrambled by the browser before it is displayed

This means that companies are most likely going to have to invest in:

Faster Servers

New 2048 bit SSL Certificates

Engineering Support

The total bill for this could range anywhere from a few hundred to many thousands of pounds depending on the size of the enterprise.